text: An advanced or future space mission must have a power source or propulsion that will require the rejection of waste heat.
  Disposing large quantities of waste heat must be considered in order to realize a large-space structure (LSS) that handle high power such as a nuclear reactor or a space solar power satellite (SPS).
  Such space systems require advanced high-temperature thermal control systems. 
  Liquid metal heat pipes with conventional radiators are considered ideally suited for such applications.
  However, the required radiator surface area is huge, hence, the system mass is very large. The liquid droplet radiator (LDR) has an advantage in terms of the rejected heat power-weight ratio. The results of the studies indicate that for rejection temperatures below approximately 700 K, the LDR system is significantly lighter in weight than the other advanced radiator concepts. A LDR can be seven times lighter than conventional heat pipe radiators of similar size.
  The LDR is more resistant to meteorite impacts due to less critical surface or windage, and requires less storage volume. 
  Therefore, the LDR has attracted attention as an advanced radiator for high-power space systems.
  In 1978, John M. Hedgepeth proposed, in "Ultralightweight Structures for Space Power," in Radiation Energy Conversion in Space, Vol. 61 of Progress in Astronautics and Aeronautics, K. W. Billman, ed. (AIAA, New York, 1978), p. 126, 
  the use of a dust radiator to reduce the radiator weight of solar power satellites. Practical problems of this dust system led to the LDR concept in 1979.
  Numerous studies have been made by companies, organizations and universities around the world.
  Practical experiments were carried out for example with STS-77 and at drop shafts in Japan: Japan Microgravity Center (JAMIC) and Microgravity Laboratory of Japan.